Rolling magnesium and magnesium alloys



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RGILLENG: MAGNESMIEE MD MAGNEfiKWM .llnlins Ziibliu, Glcrheg r, moorSicchborn, wiincrd Nib u Application November l9, llddl,

sen r un'huccz. lln swinerunc November 29, Eddil (Claims. (9311. 80 -60)It. is known that the rolling of bore and pressed rods. of magnesium andmagnesium alloys into sheets mush follow o. very different method fromclinic used with, for instance, aluminium. In addilion. to more frequentintermediate anncalings and hot; posses, other poinis musibe kept inmind in order to obtain fouli-frce sheets. In the preschi; or the cribit is not possible to roll mogneeiusn slicers using conventionallubricants beavoidance of the detachment of fine metal portlclcs fromthe rolls and their rolling into the sheets. For these reasons, afterrolling the sheets must be brushed and ground to obtain a smoothsurface. Cleaning of the rolls and grinding of the sheets involvesexpendihlre' of considerable time, the expense of the process isincreused, and the output of the rolling mill is reduced.

It has now been found that all these disadvanes can be avoided if thesurfaces of the moieriol, that is of the bars, rods or sheets to berolled, are coated with a protective layer which is maintained duringthe-whole rolling process. I'm protective layer has the great'odvantagethat the oxide skin or the metal is not damaged and dos not adhere tothe rolls. As nometal periiclcs are rolled into ihc sheet and thesurfocothereof remains mirror-smooth, brushing and g of the sheets ar nolonger necessary.

The invention will be further explained by ref- .erence to the followingexample.

The material, that is the bars, rods or sheets I to be rolled are rubbedover before or during rollms with an oil-like substance mentionedfurther mow; which has a high boiling point, of at least 200' 0., whichleaves during rolling a; resin-like, firmly adherent, plastic androllable coating, and

which forms a protective layer between the roll and thesheet. Forfurther cold or hot passes the rolls are preferably coated with the someoiltccizlve loyer; tar fat oils, tar-oils, carbolineum, anthrooene-oil,heavy oils and the constituents thereof of synthetic origin, for exampletricresyl phosphate, that; is in general oily substances in liquid,gaseous or vapour form which enable a rollable plastic resin-like layerto be formed on the metal. Adventogeously core is taken that theprotective coating, which forms this layer during rolling, is oneadopted at the same tim to hinder oxidation oi the metal duringannealing and to protect the sheets against atmospheric actionduringoizorcgew The aforementioned resin-like coating combines with andintegrates the oxide particles on the surfooe of the magnesium sheetproducing u resultant protective layer which is maintained throughoutthe entire rolling process inasmuch as it is resistant to rolling,bending, etc.

What I claim is:

l. A process for rolling magnesium and alloys thereof which comprisesthe step of providing the surface of the material to be rolled with a,resinlilre coating which contains oxide of the said materlol as ocomponent thereof and which forms a. rollable protective layer betweenroll and mabcriol.

2. A process for rolling magnesium and alloys thereof which comprisesthe steps of providing the surface of the material to be rolled with a.resinlike coating which contains oxide of the said material as acomponent thereof and which forms a rollable protective layer betweenroll and material and maintaining such layer during substantially theentire course of rolling.

3. A process for rolling magnesium and alloys thereof which comprisesthe steps of providing the surface of the material to be rolled with aresin-like coating of a. substance which combines,

with the oxide skin of the said material to form a. rollable protectivelayer between roll and material, and providing the rolls themselves witha coating of the said substance whereby said layer is renewed during therolling process.

like substance. which becomes transferred to the sheet, so that during.further procedure involving intermediate annealing, the protective layeris always renewed, The following substances can be used for example forthe formation of the pro} 4. A process for rolling magnesium and alloysthereof which comprises. the step of providing the surface of thematerial to be rolled with an oil-like coating of a substance whichforms, in combination with the oxidoskin of the said material, arollable protective layer between roll and material and also protectsthe material against oxidationduring annealing and the rolledmaterialagainst atmospheric action during storage.

5. In the rolling of magnesium and llloys thereof, the step whichcomprises rubbing on 2 the material an oil-like substance which has aboiling point of at least 200 C., which during rolling leaves, incombination with the oxide skin of the said material, a resin-like,firmly adherent and rollable coating and which forms a protective layerbetween roll and material.

6. An article for the production by rolling of sheet material ofmagnesium or magnesium alloy, comprising a billet of. the material and acoating thereon of an oil-like substance which forms, in combinationsaid material, a rollable protective layer between roll and material inthe rolling operation.

7. An article for the production by rolling of sheet material ofmagnesium or magnesium alwith the oxide skin of the as iases loy,comprising a billet oi the material and. a coating thereon or anoil-like substance which forms, in combination with the oxide skin ofthe said material, a resin-like firmly adherent and rollable layerbetween roll and material in the rolling operation. I

8. An article for the production by rolling of sheet material ofmagnesium ormagnesium a1- loy, comprising a billet of the material and acoating thereon of an oil-like substance combined with and integratingtheoxide particles on the surface of the material and which forms aresinlike firmly adherent and reliable layer between roll and materialin the rolling operatiom JULIUS ZfiBLIN.

